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排序方式: 共有312条查询结果,搜索用时 15 毫秒
91.
Jang SI Jun MH Lillehoj HS Dalloul RA Kong IK Kim S Min W 《Veterinary parasitology》2007,144(1-2):172-175
Anticoccidial effects of green tea (GT)-based diets were evaluated in chickens following oral infection with Eimeria maxima an ubiquitous intestinal parasite of poultry that impairs the growth and feed efficiency of infected birds. Five-week-old chickens were assigned to four groups (GT 0.5%, GT 2.0%, untreated/infected and non-infected control) and each group consisted of 15 chickens. Chickens were fed a standard diet supplemented with ground green tea for 2 weeks prior to infection with E. maxima (10,000 sporulated oocysts per bird). The effects of green tea on E. maxima infection were assessed by two parameters, fecal oocyst shedding and body weight gain. The green tea-fed chickens produced significantly reduced fecal oocysts (P<0.05) when compared to the E. maxima-infected group fed standard diet. The green tea-based diet, however, did not improve body weight loss caused by E. maxima infection. This study is the first to demonstrate anticoccidial effect of green tea on Eimeria parasites. 相似文献
92.
Min-Kyoung Shin Seung Hyun Yoon Myung Hwui Kim Young Soo Lyoo Seung Won Suh Han Sang Yoo 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(1):25-29
Porcine circovirus type 2 (PCV2) is the primary causative agent for post-weaning, multisystemic, wasting syndrome. Consequently, serologic detection of and vaccination against PCV2 are important for the swine industry. Among several serological tests, the enzyme-linked immunosorbent assay (ELISA) is commonly used to measure anti-PCV2 antibody levels. In the present study, we used two commercial ELISA systems to comparatively evaluate anti-PCV2 antibodies in field pigs treated with three different PCV2 vaccines. Among a total of 517 serum samples, the results of the two ELISAs were fully concordant for 365 positive and 42 negative samples, indicating 78.7% agreement. In addition, the Pearson coefficient (0.636) indicated a moderate correlation between data from the two ELISAs. Results from the farms with pigs vaccinated with the three different PCV2 vaccines demonstrated that most of the vaccinated animals underwent seroconversion. However, the increase and duration of antibody titers varied depending on the vaccine, the presence of maternal antibodies, and the vaccination program. PCV2 serologic status and anti-PCV2 antibody levels of herds from this study could be utilized to determine the best timing for vaccination and assessing vaccination compliance. 相似文献
93.
Chun-Chieh Yang Shiv O. Prasher Shaoli Wang Seung Hyun Kim Chin S. Tan Craig Drury Ramanbhai M. Patel 《Agricultural Water Management》2007
DRAINMOD-N, a mathematical model to predict nitrate-N concentrations in surface runoff and drain outflows from subsurface-drained farmlands, has been tested against field data collected in southern Ontario. The data was collected in a corn field from 16 conventional drainage and subirrigation plots in Woodslee, Ontario, from 1992 to 1994. The model performance was evaluated by comparing the observed and simulated nitrate-N concentrations in surface runoff and drain outflows. A precise calculation of water-table depth is an essential prerequisite for a model to obtain a proper prediction of nitrate-N movement. For the simulation of water-table depth, the lowest root mean square error and the highest correlation coefficient of linear regression were 173 mm and 0.51 for the subirrigation plots; and 178 mm and 0.84 for the subsurface drainage plots. Therefore, the performance of DRAINMOD-N for soil hydrologic simulations was satisfactory and it could be used for assessing nitrogen fate and transport. For the simulation of nitrate-N losses in the subirrigation plots, the lowest root mean square error and the highest correlation coefficient of linear regression were 0.74 kg/ha and 0.98 for surface runoff; and 6.53 kg/ha and 0.91 for drain outflow. For the simulation in the subsurface drainage plots, the lowest root mean square error and the highest correlation coefficient of linear regression were 0.70 kg/ha and 0.96 for surface runoff; and 6.91 kg/ha and 0.92 for drain outflow. The results show that DRAINMOD-N can perform satisfactory simulation of soil hydrology and nitrate-N losses in surface runoff under various water-table management practices. The model can, therefore, be used to evaluate different water pollution scenarios and help in the development and testing of various pollution control strategies for fields in cold weather such as that in southern Canada. 相似文献
94.
Seung Hun Jeong Hyoung Kyu Kim In-Sung Song Seon Joong Lee Kyung Soo Ko Byoung Doo Rhee Nari Kim Natalia P. Mishchenko Sergey A. Fedoryev Valentin A. Stonik Jin Han 《Marine drugs》2014,12(5):2922-2936
Echinochrome A (Ech A) is a naphthoquinoid pigment from sea urchins that possesses antioxidant, antimicrobial, anti-inflammatory and chelating abilities. Although Ech A is the active substance in the ophthalmic and cardiac drug Histochrome®, its underlying cardioprotective mechanisms are not well understood. In this study, we investigated the protective role of Ech A against toxic agents that induce death of rat cardiac myoblast H9c2 cells and isolated rat cardiomyocytes. We found that the cardiotoxic agents tert-Butyl hydroperoxide (tBHP, organic reactive oxygen species (ROS) inducer), sodium nitroprusside (SNP; anti-hypertension drug), and doxorubicin (anti-cancer drug) caused mitochondrial dysfunction such as increased ROS level and decreased mitochondrial membrane potential. Co-treatment with Ech A, however, prevented this decrease in membrane potential and increase in ROS level. Co-treatment of Ech A also reduced the effects of these cardiotoxic agents on mitochondrial oxidative phosphorylation and adenosine triphosphate level. These findings indicate the therapeutic potential of Ech A for reducing cardiotoxic agent-induced damage. 相似文献
95.
The phase transition behavior and isothermal micro-phase separation kinetics of polyester-based thermoplastic elastomer were
studied using the synchrotron X-ray scattering (SAXS) method. The structural changes occurring during heating period were
investigated by determining the changes of the one-dimensional correlation function, interfacial thickness and Porod constant.
Based on the abrupt increases of the domain spacing and interfacial thickness, a major structural change occurring well below
the melting transition temperature is suggested. Those changes are explained in terms of melting of the thermodynamically
unstable hard domains or/and the interdiffusion of the hard and soft segments in the interfacial regions. SAXS profile changes
during the micro-phase separation process were also clearly observed at various temperatures and the separation rate was found
to be sensitively affected by the temperature. The peak position of maximum scattering intensity stayed constant during the
entire course of the phase separation process. The scattering data during the isothermal phase separation process was interpreted
with the Cahn-Hilliard diffusion equation. The experimental data obtained during the early stage of the phase separation seems
to satisfy the Cahn-Hilliard spinodal mechanism. The transition temperature obtained from the extrapolation of the diffusion
coefficient to zero value turned out to be about 147±2°C, which is close to the order-disorder transition temperature obtained
from the Porod analysis. The transition temperature was also estimated from the invariant growth rate. By extrapolating the
invariant growth rate to zero, a transition temperature of about 145±2°C was obtained. 相似文献
96.
Polyvinyl chloride (PVC) fibers were melt-spun to prepare mono and multifilament yarns. To find optimum spinning and drawing
conditions, various parameters such as spinning temperature, spinneret diameter, drawing temperature, and drawing ratio were
examined. From the observation of the spinnability under various conditions, we found that the optimum conditions were as
following: the extrusion temperature and die temperature were 175–180°C and 185–190°C, and the drawing temperature and drawing
ratio were 85–95°C and 3.4, respectively. Under these conditions, the spinneret diameter could be reduced to the minimum value,
0.5 mm. Spun PVC filament yarns were subjected to the different yarn texturing process of stuffing box and pin false-twist
method. The PVC yarn fabric was prepared by the knitting of textured yarns. Finally, the anion-emission and antibiotic properties
of the knitted PVC fabrics were precisely evaluated. 相似文献
97.
This paper suggests the optimal conditions to prevent electrostatic charge in the laundry by the evaluation of the electrostatic
characteristics during the drying process. Cotton, nylon, and polyester fabrics were used as test specimens, employing the
standard washing cycle. The electrostatic characteristics of the laundry were measured after the automatic drying process.
This paper investigates the optimal conditions for preventing electrostatic charges in laundry by evaluating the electrostatic
characteristics that occur during the drying process. Cotton, nylon, and polyester fabrics were used as the test specimens,
employing a standard washing cycle. The electrostatic characteristics of the laundry were measured immediately after the automatic
drying process. The results, showed that the moisture content decreased and the electrostatic charge increased with drying
time. The specimen fabrics had already dried up before completion of the standard drying cycle. Consequently, the excessive
drying generated an electrostatic charge due to removal of the traces of remaining moisture and the resulting excessive friction.
For cotton fabrics, the electrostatic charge was under 1000 V even for the maximum drying time due to the intrinsic high moisture
regain of cotton. On the other hand, the electrostatic charge produced for nylon fabrics increased rapidly with the drying
time, and amounted up to approximately 8000V after 120 minutes. The results also indicated that the electrostatic charge could
be decreased by drying fabrics of only one kind. When mixed kinds of fabrics were dried, the electrostatic charge increased
remarkably. Therefore, it is suggested that laundry be classified and washed according to the kinds of fiber, and not be dried
excessively to reduce electrostatic charge. In addition, the proper use of a softener is effective in reducing the electrostatic
charge. 相似文献
98.
Short wool fibers obtained by the stretch breaking process can be blended with cotton fibers and processed in a cotton spinning
system, which has a high production rate. For the structural property of the wool fiber after stretch breaking, the diameter
and length of the wool fiber were measured as a function of time. The diameter of the broken fibers was finer than the diameter
of untreated fibers. The fiber diameter at the break point was the finest and was more irregular than the original fiber.
The broken fiber showed mechanical properties of increased modulus, decreased breaking strain, and increased breaking strength. 相似文献
99.
Doo Hyun Baik Hae Young Kim Sun Jin Kwon Myung Hyun Kwon Han Sup Lee Ji Ho Youk Seung Won Seo 《Fibers and Polymers》2006,7(4):367-371
Thermal properties of copolyetherester/silica nanocomposites were examined by using DSC and TGA. The segmented block copolyetheresters
with various hard segment structures and hard segment contents (HSC) were synthesized and their silica nanocomposite films
were prepared by solution casting method. The nano-sized fumed silica particles were found to act as a nucleating agent of
the copolyetheresters. The nanocomposites always showed reduced degree of supercooling or faster crystallization than the
corresponding copolyetheresters. The nanocomposites also showed increased hard segment crystallinity except HSC 35 sample
which had short hard segment length. In case of 2GT [poly(ethylene terephthalate)] copolyetheresters, which were not developed
commercially because of their low crystallization rate, the hard segment crystallinity increased considerably. The copolyetherester/silica
nanocomposites showed better thermal stability than copolyetheresters. 相似文献
100.
Waterproof fabrics are seamed and sealed by waterproof sealing tape to prevent water from penetrating through the stitch holes.
As this process may change the mechanical properties of breathable waterproof fabric related to its deformation with human
body, the changes in mechanical properties were investigated. In both of parallel and perpendicular directions, tensile characteristics
were remarkably changed with seaming and sealing processes. The increase of LT and WT means that the clothing sealed by waterproofing
tape may produce somewhat discomfort feeling. On the other hand, the bridge of the sewing thread seemed to be reinforced by
waterproofing tape. Shear characteristics such as G, 2HG, and 2HG5 gradually increased with seaming and sealing processes
in parallel direction. However, they decreased with sealing process in perpendicular direction because the seam line work
as an axis located at the center of the testing range. 相似文献